Searches for High Redshift Radio Galaxies

Breuck, C. De; Breugel, Wil van; Röttgering, H. J. A.; Miley, G. K.

doi:10.1007/978-94-011-5238-9_32

Cited by 185 publications

(364 citation statements)

References 7 publications

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“…We have detected N V in the northern region, which is seldom present at a significant level in HzRGs Röttgering et al (1997), De Breuck et al (2000. In the southern region we detected no N V, while the other line-ratios are similar in both regions.…”

Section: Difference In N V Emission From the Two Regions: Evidence Fosupporting

confidence: 49%

Deep VLT spectroscopy of the $\vec{z}=$ 2.49 radio galaxy MRC 2104-242

Overzier

Röttgering

Kurk

et al. 2001

A&A

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Abstract. We present spectroscopic observations of the rest-frame UV line emission around radio galaxy MRC 2104-242 at z = 2.49, obtained with FORS1 on VLT Antu. The morphology of the halo is dominated by two spatially resolved regions. Lyα is extended by >12 along the radio axis, C IV and He II are extended by ∼8 . The overall spectrum is typical for that of high redshift radio galaxies. The most striking spatial variation is that N V is present in the spectrum of the region associated with the center of the galaxy hosting the radio source, the northern region, while absent in the southern region. Assuming that the gas is photoionized by a hidden quasar, the difference in N V emission can be explained by a metallicity gradient within the halo, with the northern region having a metallicity of Z ≈ 1.5 Z and Z ≤ 0.4 Z for the southern region. This is consistent with a scenario in which the gas is associated with a massive cooling flow or originates from the debris of the merging of two or more galaxies.

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Section: Difference In N V Emission From the Two Regions: Evidence Fosupporting

confidence: 49%

Deep VLT spectroscopy of the $\vec{z}=$ 2.49 radio galaxy MRC 2104-242

Overzier

Röttgering

Kurk

et al. 2001

A&A

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“…1, solar or super-solar metallicities are common in quasars up to high redshifts. This does not only refer to so-called "α-elements" being rapidly synthesized in short-lived massive stars but also to iron (e.g., Iwamuro et al 2004;Kurk et al 2007;Sameshima et al 2009), carbon (e.g., Jiang et al 2007;Juarez et al 2009), and, even more importantly, nitrogen (Hamann & Ferland 1999;De Breuck et al 2000;Vernet et al 2001;Hamann et al 2002;Nagao et al 2006;Matsuoka et al 2009), with 14 N being mainly a secondary nucleus produced by CNO burning just like 13 C. A possible explanation for the contradictory results obtained at or near optical wavelengths and the microwave data presented here may be different locations. It is well possible that mainly secondary nuclei like 13 C and 14 N are enriched close to the quasar, in the Broad and Narrow Line Regions and in outflows originating from the active galactic nucleus (AGN).…”

Section: 3mentioning

confidence: 99%

Weak¹³CO in the Cloverleaf quasar: evidence for a young, early generation starburst

Henkel¹,

Downes

Weiß³

et al. 2010

A&A

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Observations of 12 CO at high redshift indicate rapid metal enrichment in the nuclear regions of at least some galaxies in the early universe. However, the enrichment may be limited to nuclei that are synthesized by short-lived massive stars, excluding classical "secondary" nuclei like 13 C. Testing this idea, we used the IRAM Interferometer to tentatively detect the 13 CO J = 3 → 2 line at a level of 0.3 Jy km s −1 toward the Cloverleaf quasar at z = 2.5. This is the first observational evidence for 13 C at high redshift. The 12 CO/ 13 CO J = 3 → 2 luminosity ratio is with 40 +25 −8 much higher than ratios observed in molecular clouds of the Milky Way and in the ultraluminous galaxy Arp 220, but may be similar to that observed toward NGC 6240. Large Velocity Gradient models simulating seven 12 CO transitions and the 13 CO line yield 12 CO/ 13 CO abundance ratios in excess of 100. It is possible that the measured ratio is affected by a strong submillimeter radiation field, which reduces the contrast between the 13 CO line and the background. It is more likely, however, that the ratio is caused by a real deficiency of 13 CO. This is already apparent in local ultraluminous galaxies and may be even more severe in the Cloverleaf because of its young age ( < ∼ 2.5 Gyr). A potential conflict with optical data, indicating high abundances also for secondary nuclei in quasars of high redshift, may be settled if the bulk of the CO emission is originating sufficiently far from the active galactic nucleus of the Cloverleaf.

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“…Their models assume solar metallicities, shock velocities from 150 to 500 km s À1 , and the magnetic parameter 0 lG cm 3=2 B= ffiffi ffi n p 4 lG cm 3/2 . The PNN photoionization model results are shown together with these models in Figure 6, the UV emission-line diagnostic diagrams proposed by De Breuck et al (2000).…”

Section: No 1 2002mentioning

confidence: 93%

“…In Figure 6, we plot the observed positions of IRAS F10214+4714 (Serjeant et al 1998) and the high-z powerful radio galaxies studied by De Breuck et al (2000). Although the high-z powerful radio galaxies have an AGN, at least some of them are considered to be very young galaxies (e.g., Eales et al 1993).…”

Section: Comparison With High-z Star-forming Galaxiesmentioning

confidence: 99%

Effects of a Burst of Formation of First‐Generation Stars on the Evolution of Galaxies

Shioya

Taniguchi

Murayama

et al. 2002

ApJ

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First-generation (Population III) stars in the universe play an important role in the early enrichment of heavy elements in galaxies and intergalactic medium and thus affect the history of galaxies. The physical and chemical properties of primordial gas clouds are significantly different from those of present-day gas clouds observed in the nearby universe because the primordial gas clouds do not contain any heavy elements, which are important coolants in gas. Previous theoretical considerations have suggested that typical masses of the first-generation stars are between several solar masses and %10 M , although it has been argued that the formation of very massive stars (e.g., >100 M ) is also likely. If stars with several solar masses are the most popular ones at the epoch of galaxy formation, most stars will evolve to hot (e.g., e10 5 K), luminous ($10 4 L ) stars with gaseous and dusty envelopes prior to going on to die as white dwarf stars. Although the duration of this phase is short (e.g., $10 5 yr), such evolved stars could contribute both to the ionization of gas in galaxies and to the production of a lot of dust grains if the formation of intermediate-mass stars is highly enhanced. We compare gaseous emission-line properties of such nebulae with some interesting highredshift galaxies such as IRAS F10214+4724 and powerful radio galaxies.

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Searches for High Redshift Radio Galaxies

Cited by 185 publications

References 7 publications

Deep VLT spectroscopy of the $\vec{z}=$ 2.49 radio galaxy MRC 2104-242

Deep VLT spectroscopy of the $\vec{z}=$ 2.49 radio galaxy MRC 2104-242

Weak¹³CO in the Cloverleaf quasar: evidence for a young, early generation starburst

Effects of a Burst of Formation of First‐Generation Stars on the Evolution of Galaxies

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Searches for High Redshift Radio Galaxies

Cited by 185 publications

References 7 publications

Deep VLT spectroscopy of the $\vec{z}=$ 2.49 radio galaxy MRC 2104-242

Deep VLT spectroscopy of the $\vec{z}=$ 2.49 radio galaxy MRC 2104-242

Weak13CO in the Cloverleaf quasar: evidence for a young, early generation starburst

Effects of a Burst of Formation of First‐Generation Stars on the Evolution of Galaxies

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Weak¹³CO in the Cloverleaf quasar: evidence for a young, early generation starburst